For two months the trapped miners in Chile have endured 90% humidity and intermittent supplies of food and water, while having to clear part of the mine shaft to ensure their imminent rescue runs as smoothly as possible.

In terms of physical health, the men have done well, taking part in an exercise regime designed to improve their fitness in preparation for the gruelling one-hour trip that each one will soon take back to the surface.

But the mental health of the trapped miners is a different issue. Doctors have warned that depression is a serious risk in the wake of the long period of isolation and constant darkness that the men have been through. Extended periods of darkness interrupt the circadian rhythm, the day-night cycle which controls human body clocks. As a result, the miners may experience intense fatigue similar to that felt by travellers suffering from jet lag.

To counteract this, LEDs designed to represent sunlight have been sent down the mine to trick the miners' body clocks back into something resembling normal operation. Magazines, bibles and journals have also been sent down through supply tubes, as well as a communal iPod with speakers and a video camera for the men to record messages for their families. A request for cigarettes was accepted after an improvement in the mine's ventilation was achieved.

Some demands have been turned down; iPods with personal headphones were rejected because of fears they may isolate the men from one another and reduce the feeling of togetherness that has proved so valuable to their survival.

The intense boredom suffered by the miners has also concerned medics, and a fibre optic projector has been sent down to screen movies, television and sports events. Psychiatrists warned against showing emotionally intense dramas because of the increased risk of depression among the men.

There are some things that cannot be predicted, however. On 7 September it was decided that a live football match between Chile and Ukraine should be screened for the men. Unfortunately, Chile lost 2-1.